slave route, I can't even consider that. Mostly because it's called the slave route...How can Lin respect you when you have elven slaves under your rule...Best to do both, there is more sex on the slave route for now, but more story in the love one. There is going to be more sex in the love one too, but it will take longer to happen.
If all you care about is the sex, do the slave route, if you care about story and the characters, then do the love one.